1. Field of the Invention
This invention relates to master cylinders for hydraulic brake systems for vehicles and in particular, to a divided master cylinder constructed with dual opposing pistons whereby if one of the sides of the master cylinder or the hydraulic circuit componentry, seals, or hoses should fail, the other side of the master cylinder and its corresponding hydraulic circuit will maintain the braking operation.
2. Description of the Related Art
A major problem with braking systems for motor vehicles and like vehicles is the failure of hydraulic pressure due to seal leaks, hose failure and the like whereby due to the lack of hydraulic pressure the brakes are unable to operate in an effective manner. Such lack of operation can be catastrophic and lead to fatalities.
There have been many proposals to alleviate brake failures by a variety of methods which are complicated and costly, however, it is believed that none of these methods provide sufficient reliability to help avert brake failure.
A major disadvantage of currently manufactured tandem brake master cylinders is the length of cylinder body housing. This is both costly to manufacture as well as encroaching on limited engine compartment space. Current designs also use a single sliding elastomeric rubber seal to divide the primary and secondary sections. The use of such a seal results in increased pedal travel due to seal compression and deflection and reduced secondary section output pressure due to frictional losses. One further possible drawback is that in the unlikely event of two problems arising simultaneously, such as a hose failure and the dividing seal failure, total loss of brake fluid could occur with corresponding total loss of vehicle braking.